Daniel described his colors trilogy project as the process of finding his true colors and CYAN as the “first button” in that process. With CYAN he wanted to project positive energy and put his dreams, passion, and challenges into the clear and fresh color of cyan. He took part in the process of making the album from track selection to choosing the themes, as he believes he’s the only person who truly knows what he’s good at. He also took part in the choreography and was involved in the production of his music video.^{[s] [s]}

In an interview with Grazia Korea, Daniel was asked about the goal of this first installment. He responded that the album was released shortly after his break, so he wanted the songs to be enjoyable to listen to. Just hearing that his songs were good meant he achieved his goals. CYAN was about new songs, and the next album in the trilogy encompasses what he is good at.^[s]

The lead single’s name is a play on the English meaning “to you” and the literal Korean pronunciation “reason” (이유, iyu) since “two” is also read as 이. “2U” contains a message to a weary or lonely person running after their dreams: There are those who stay by your side who love you because you are you.^[s]

“2U” was written and composed by Korean-American artist Chancellor with Daniel in mind. Even during Chancellor’s initial working stages with the song, Daniel thought it matched him well. He described “2U” as a mix of pop and hip-hop with a “gentle and comfortable” sound and a “warm song like the sunny spring weather”.^[s] He recommended “2U” as a car drive song. As part of Grazia Korea‘s May cover story, Daniel was asked if there was a specific reason for choosing groovy title tracks such as “2U” despite others thinking of him as an artist with powerful, strong performances. He replied that he wanted to show what he is capable of step-by-step to heighten the sense of tension.

In his Pops in Seoul interview, he confessed “2U” was not the title track at first. His comeback in winter was postponed due to personal reasons. After considering what song would match freshness, “2U” was selected. “Jealous” was the last song included in the album, but Daniel thought it was the most fitting with CYAN. He introduced “Jealous” as “hanging out with friends at night” and looking so happy that it makes people jealous.^{[s] [s]} He liked “Interview” the best since he thought the song and his voice matched well.^[s]